_javascript techniques for array sort and reverse usage analysis in JavaScript

The examples in this article describe the array sort and reverse usage in JavaScript. Share to everyone for your reference. The specific analysis is as follows:

The sort () method is used to sort the elements of an array.

Reverse () to reverse the elements in an array

First, let's try the following code:

Copy Code code as follows:

var values = [1, 0, 5, 15, 10];
Values.reverse ();
Console.log (values);

What would the output be:
[10, 15, 5, 0, 1]

Reverse () is simply to turn the array upside down, so the next thing you want to spit out is sort ()

Copy Code code as follows:

var values = [1, 0, 5, 15, 10];
Values.sort ();
Console.log (values);

The output of this function turns out to be:
[0, 1, 10, 15, 5]

What's going on?

In fact, the sort () function uses the ToString () transformation, and string comparisons are ASCII, so it's better if we need to sort, or write ourselves a sort ().

Copy Code code as follows:

var values = [1, 0, 5, 15, 10];
function Compare (value1, value2) {
if (value1 < value2) {
return-1;
else if (value1 > value2) {
return 1;
} else {
return 0;
}
}
Values.sort (Compare);
Console.log (values);

If you change it-1 and 1, you can sort it backwards.

Now the output results:
[0, 1, 5, 10, 15]

A simpler formulation is to use return value2-value1 inside the Compare ().

I hope this article will help you with your JavaScript programming.